A conventional control apparatus for a multi-cylinder internal combustion engine is disclosed, for example, in Patent Document 1. The aforementioned conventional control apparatus is configured so that, at a time of reduced-cylinder operation that halts the operation of some cylinders, operation of an intake valve in a halted cylinder is stopped at the closed position. In addition, the aforementioned conventional control apparatus is configured so as to retard an opening timing of an exhaust valve in a halted cylinder so as to be a predetermined timing that is after the expansion bottom dead center, and to also advance a closing timing of the relevant exhaust valve so as to be a predetermined timing that is before the exhaust top dead center. According to this control, in the halted cylinder in which the intake valve is placed in a closed-valve stopped state, exhaust gas can be caused to remain inside the halted cylinder by advancing the closing timing of the exhaust valve. It is thereby possible to suppress the occurrence of a state in which an excessive negative pressure is generated inside the halted cylinder, and suppress an oil ascent in the halted cylinder.
The applicants are aware of the following documents, which includes the above described document, as documents related to the present invention.